Semiconductor substrate supports with improved high temperature chucking

ABSTRACT

Exemplary support assemblies may include an electrostatic chuck body defining a substrate support surface. The assemblies may include a support stem coupled with the electrostatic chuck body. The assemblies may include a heater embedded within the electrostatic chuck body. The assemblies may also include an electrode embedded within the electrostatic chuck body between the heater and the substrate support surface. The substrate support assemblies may be characterized by a leakage current through the electrostatic chuck body of less than or about 4 mA at a temperature of greater than or about 500° C. and a voltage of greater than or about 600 V.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of, and priority to U.S.Provisional Patent Application No. 62/879,696, filed Jul. 29, 2019, thecontents of which are hereby incorporated by reference in their entiretyfor all purposes.

TECHNICAL FIELD

The present technology relates to components and apparatuses forsemiconductor manufacturing. More specifically, the present technologyrelates to substrate support assemblies and other semiconductorprocessing equipment.

BACKGROUND

Integrated circuits are made possible by processes which produceintricately patterned material layers on substrate surfaces. Producingpatterned material on a substrate requires controlled methods forforming and removing material. The temperature at which these processesoccur may directly impact the final product. Substrate temperatures areoften controlled and maintained with the assembly supporting thesubstrate during processing. Internally located heating devices maygenerate heat within the support, and the heat may be transferredconductively to the substrate. The substrate support may also beutilized in some technologies to develop a substrate-level plasma.Plasma generated near the substrate may cause bombardment of components,as well as parasitic plasma formation in unfavorable regions of thechamber. Additionally, utilizing the pedestal for both heat generationand plasma generation may cause interference effects.

As a variety of operational processes may utilize increased temperatureas well as substrate-level plasma formation, constituent materials ofthe substrate support may be exposed to temperatures that affect theelectrical operations of the assembly. Thus, there is a need forimproved systems and methods that can be used to produce high qualitydevices and structures. These and other needs are addressed by thepresent technology.

SUMMARY

Exemplary support assemblies may include an electrostatic chuck bodydefining a substrate support surface. The assemblies may include asupport stem coupled with the electrostatic chuck body. The assembliesmay include a heater embedded within the electrostatic chuck body. Theassemblies may also include an electrode embedded within theelectrostatic chuck body between the heater and the substrate supportsurface. The substrate support assemblies may be characterized by aleakage current through the electrostatic chuck body of less than orabout 4 mA at a temperature of greater than or about 500° C. and avoltage of greater than or about 600 V.

In some embodiments, the substrate support surface may define a recessedledge extending radially inward from an outer radial edge of therecessed pocket. The electrostatic chuck body may define a plurality ofprotrusions extending from the substrate support surface within therecessed pocket. A distance between a radially outermost protrusion andin inner radial edge of the recessed ledge may be maintained below orabout 3 mm. The electrostatic chuck body may define greater than orabout 500 protrusions, and each protrusion of the plurality ofprotrusions may be characterized by a diameter of greater than or about1 mm. A subset of protrusions of the plurality of protrusions may becharacterized by a diameter of greater than or about 2 mm. The pluralityof protrusions may define a contact area for a substrate seated on thesubstrate support surface of the electrostatic chuck body, and thecontact area may be less than or about 10% of a planar area of thesubstrate. The electrostatic chuck body may include a ceramic material.The ceramic material may be or include aluminum nitride. The ceramicmaterial may be characterized by a volumetric resistivity of greaterthan or about 1×109 ohm-cm at a temperature of greater than or about550° C.

Some embodiments of the present technology may encompass substratesupport assemblies. The substrate support assemblies may include anelectrostatic chuck body defining a substrate support surface. Theassemblies may include a heater embedded within the electrostatic chuckbody. The assemblies may include an electrode embedded within theelectrostatic chuck body between the heater and the substrate supportsurface. The electrode may be maintained a distance of at least about 3mm from the substrate support surface within the electrostatic chuckbody. The substrate support assembly may be characterized by a leakagecurrent through the electrostatic chuck body of less than or about 4 mAat a temperature of greater than or about 540° C. and a voltage ofgreater than or about 660 V.

In some embodiments the electrode may be positioned within theelectrostatic chuck body at a depth of at least about 5 mm from thesubstrate support surface of the electrostatic chuck body. Theelectrostatic chuck body may include a ceramic material characterized bya volumetric resistivity of greater than or about 1×109 ohm-cm at atemperature of greater than or about 600° C. The electrostatic chuckbody may define a recessed pocket within the substrate support surfaceconfigured to receive a substrate for processing. The substrate supportsurface may define a recessed ledge extending radially inward from anouter radial edge of the recessed pocket. The electrostatic chuck bodymay define a plurality of protrusions extending from the substratesupport surface within the recessed pocket. The plurality of protrusionsmay define a contact area for a substrate seated on the substratesupport surface of the electrostatic chuck body. The contact area may beless than or about 5% of a planar area of the substrate. The substratesupport assembly may be characterized by a leakage current through theelectrostatic chuck body of less than or about 4 mA at a temperature ofgreater than or about 600° C. and a voltage of greater than or about 800V.

Some embodiments of the present technology may encompass substratesupport assemblies. The assemblies may include an electrostatic chuckbody defining a substrate support surface. The assemblies may include asupport stem coupled with the electrostatic chuck body. The assembliesmay include a heater embedded within the electrostatic chuck body. Theassemblies may include an electrode embedded within the electrostaticchuck body between the heater and the substrate support surface. Theelectrode may be maintained a distance of at least about 5 mm from thesubstrate support surface within the electrostatic chuck body. Thesubstrate support assembly may be characterized by a leakage currentthrough the electrostatic chuck body of less than or about 4 mA at atemperature of greater than or about 550° C. and a voltage of greaterthan or about 650 V.

Such technology may provide numerous benefits over conventional systemsand techniques. For example, embodiments of the present technology mayprovide substrate supports that may both facilitate substrate-levelplasmas, and may remain sustainable during high-temperature operations.Additionally, by providing reduced leakage currents relative toconventional technologies, an increased voltage chucking window may beafforded. These and other embodiments, along with many of theiradvantages and features, are described in more detail in conjunctionwith the below description and attached figures.

BRIEF DESCRIPTION OF THE DRAWINGS

A further understanding of the nature and advantages of the disclosedtechnology may be realized by reference to the remaining portions of thespecification and the drawings.

FIG. 1 shows a top plan view of an exemplary processing system accordingto some embodiments of the present technology.

FIG. 2 shows a schematic cross-sectional view of an exemplary plasmasystem according to some embodiments of the present technology.

FIG. 3 shows a schematic partial cross-sectional view of an exemplarysubstrate support assembly according to some embodiments of the presenttechnology.

FIG. 4 shows a schematic partial cross-sectional view of an exemplarysubstrate support assembly according to some embodiments of the presenttechnology.

FIG. 5 shows a schematic partial top plan view of an exemplary substratesupport assembly according to some embodiments of the presenttechnology.

Several of the figures are included as schematics. It is to beunderstood that the figures are for illustrative purposes, and are notto be considered of scale unless specifically stated to be of scale.Additionally, as schematics, the figures are provided to aidcomprehension and may not include all aspects or information compared torealistic representations, and may include exaggerated material forillustrative purposes.

In the appended figures, similar components and/or features may have thesame reference label. Further, various components of the same type maybe distinguished by following the reference label by a letter thatdistinguishes among the similar components. If only the first referencelabel is used in the specification, the description is applicable to anyone of the similar components having the same first reference labelirrespective of the letter.

DETAILED DESCRIPTION

Plasma enhanced deposition processes may energize one or moreconstituent precursors to facilitate film formation on a substrate.These formed films may be produced under conditions that cause stresseson the substrate. For example, in the development of dielectric layersfor vertical memory applications, such as ON stacks, many layers ofmaterial may be deposited on a substrate. These produced films may becharacterized by internal stresses that act upon the substrate. This maycause a substrate to bow during processing, which can lead to pooruniformity of formation, as well as device damage or malfunction.

An electrostatic chuck may be used to produce a clamping action againstthe substrate to overcome the bowing stress. However, as these devicestacks increase in numbers of layers, the stresses acted upon thesubstrate increase, which may require a proportional increase inchucking voltage. Additionally, many of these films may be developed atrelatively high temperatures that further affect components of thechamber. For example, some deposition activities may occur attemperatures above 500° C. or higher, which may affect the resistivityof chamber components, such as the materials of the electrostatic chuck.As the resistivity of the material reduces, current leakage mayincrease. When compounded with the increased voltages used to overcomethe bowing stresses exerted on the substrate with increased depositionlayers, electric arcs may be produced, which can damage substrates andchamber components. These issues have limited conventional technologiesto narrow chucking windows that cannot accommodate increased scaling oflayers during deposition.

The present technology overcomes these challenges with substrate supportassemblies having particular materials and configurations exhibitingspecific electrical characteristics that may produce reduced leakagecurrents over conventional technologies, especially at increasedtemperatures. Additionally, the assemblies may include surfacetopographies that facilitate clamping of substrates having stressescorresponding to increased layers of deposition.

Although the remaining disclosure will routinely identify specificdeposition processes utilizing the disclosed technology, it will bereadily understood that the systems and methods are equally applicableto other deposition and cleaning chambers, as well as processes as mayoccur in the described chambers. Accordingly, the technology should notbe considered to be so limited as for use with these specific depositionprocesses or chambers alone. The disclosure will discuss one possiblesystem and chamber that may include pedestals according to embodimentsof the present technology before additional variations and adjustmentsto this system according to embodiments of the present technology aredescribed.

FIG. 1 shows a top plan view of one embodiment of a processing system100 of deposition, etching, baking, and curing chambers according toembodiments. In the figure, a pair of front opening unified pods 102supply substrates of a variety of sizes that are received by roboticarms 104 and placed into a low pressure holding area 106 before beingplaced into one of the substrate processing chambers 108 a-f, positionedin tandem sections 109 a-c. A second robotic arm 110 may be used totransport the substrate wafers from the holding area 106 to thesubstrate processing chambers 108 a-f and back. Each substrateprocessing chamber 108 a-f, can be outfitted to perform a number ofsubstrate processing operations including formation of stacks ofsemiconductor materials described herein in addition to plasma-enhancedchemical vapor deposition, atomic layer deposition, physical vapordeposition, etch, pre-clean, degas, orientation, and other substrateprocesses including, annealing, ashing, etc.

The substrate processing chambers 108 a-f may include one or more systemcomponents for depositing, annealing, curing and/or etching a dielectricor other film on the substrate. In one configuration, two pairs of theprocessing chambers, e.g., 108 c-d and 108 e-f, may be used to depositdielectric material on the substrate, and the third pair of processingchambers, e.g., 108 a-b, may be used to etch the deposited dielectric.In another configuration, all three pairs of chambers, e.g., 108 a-f,may be configured to deposit stacks of alternating dielectric films onthe substrate. Any one or more of the processes described may be carriedout in chambers separated from the fabrication system shown in differentembodiments. It will be appreciated that additional configurations ofdeposition, etching, annealing, and curing chambers for dielectric filmsare contemplated by system 100.

FIG. 2 shows a schematic cross-sectional view of an exemplary plasmasystem 200 according to some embodiments of the present technology.Plasma system 200 may illustrate a pair of processing chambers 108 thatmay be fitted in one or more of tandem sections 109 described above, andwhich may include substrate support assemblies according to embodimentsof the present technology. The plasma system 200 generally may include achamber body 202 having sidewalls 212, a bottom wall 216, and aninterior sidewall 201 defining a pair of processing regions 220A and220B. Each of the processing regions 220A-220B may be similarlyconfigured, and may include identical components.

For example, processing region 220B, the components of which may also beincluded in processing region 220A, may include a pedestal 228 disposedin the processing region through a passage 222 formed in the bottom wall216 in the plasma system 200. The pedestal 228 may provide a heateradapted to support a substrate 229 on an exposed surface of thepedestal, such as a body portion. The pedestal 228 may include heatingelements 232, for example resistive heating elements, which may heat andcontrol the substrate temperature at a desired process temperature.Pedestal 228 may also be heated by a remote heating element, such as alamp assembly, or any other heating device.

The body of pedestal 228 may be coupled by a flange 233 to a stem 226.The stem 226 may electrically couple the pedestal 228 with a poweroutlet or power box 203. The power box 203 may include a drive systemthat controls the elevation and movement of the pedestal 228 within theprocessing region 220B. The stem 226 may also include electrical powerinterfaces to provide electrical power to the pedestal 228. The powerbox 203 may also include interfaces for electrical power and temperatureindicators, such as a thermocouple interface. The stem 226 may include abase assembly 238 adapted to detachably couple with the power box 203. Acircumferential ring 235 is shown above the power box 203. In someembodiments, the circumferential ring 235 may be a shoulder adapted as amechanical stop or land configured to provide a mechanical interfacebetween the base assembly 238 and the upper surface of the power box203.

A rod 230 may be included through a passage 224 formed in the bottomwall 216 of the processing region 220B and may be utilized to positionsubstrate lift pins 261 disposed through the body of pedestal 228. Thesubstrate lift pins 261 may selectively space the substrate 229 from thepedestal to facilitate exchange of the substrate 229 with a robotutilized for transferring the substrate 229 into and out of theprocessing region 220B through a substrate transfer port 260.

A chamber lid 204 may be coupled with a top portion of the chamber body202. The lid 204 may accommodate one or more precursor distributionsystems 208 coupled thereto. The precursor distribution system 208 mayinclude a precursor inlet passage 240 which may deliver reactant andcleaning precursors through a dual-channel showerhead 218 into theprocessing region 220B. The dual-channel showerhead 218 may include anannular base plate 248 having a blocker plate 244 disposed intermediateto a faceplate 246. A radio frequency (“RF”) source 265 may be coupledwith the dual-channel showerhead 218, which may power the dual-channelshowerhead 218 to facilitate generating a plasma region between thefaceplate 246 of the dual-channel showerhead 218 and the pedestal 228.In some embodiments, the RF source may be coupled with other portions ofthe chamber body 202, such as the pedestal 228, to facilitate plasmageneration. A dielectric isolator 258 may be disposed between the lid204 and the dual-channel showerhead 218 to prevent conducting RF powerto the lid 204. A shadow ring 206 may be disposed on the periphery ofthe pedestal 228 that engages the pedestal 228.

An optional cooling channel 247 may be formed in the annular base plate248 of the gas distribution system 208 to cool the annular base plate248 during operation. A heat transfer fluid, such as water, ethyleneglycol, a gas, or the like, may be circulated through the coolingchannel 247 such that the base plate 248 may be maintained at apredefined temperature. A liner assembly 227 may be disposed within theprocessing region 220B in close proximity to the sidewalls 201, 212 ofthe chamber body 202 to prevent exposure of the sidewalls 201, 212 tothe processing environment within the processing region 220B. The linerassembly 227 may include a circumferential pumping cavity 225, which maybe coupled to a pumping system 264 configured to exhaust gases andbyproducts from the processing region 220B and control the pressurewithin the processing region 220B. A plurality of exhaust ports 231 maybe formed on the liner assembly 227. The exhaust ports 231 may beconfigured to allow the flow of gases from the processing region 220B tothe circumferential pumping cavity 225 in a manner that promotesprocessing within the system 200.

FIG. 3 shows a schematic partial cross-sectional view of an exemplarysemiconductor processing chamber 300 according to some embodiments ofthe present technology. FIG. 3 may include one or more componentsdiscussed above with regard to FIG. 2, and may illustrate furtherdetails relating to that chamber. The chamber 300 may be used to performsemiconductor processing operations including deposition of stacks ofdielectric materials as previously described. Chamber 300 may show apartial view of a processing region of a semiconductor processingsystem, and may not include all of the components, such as additionallid stack components previously described, which are understood to beincorporated in some embodiments of chamber 300.

As noted, FIG. 3 may illustrate a portion of a processing chamber 300.The chamber 300 may include a showerhead 305, as well as a substratesupport assembly 310. Along with chamber sidewalls 315, the showerhead305 and the substrate support 310 may define a substrate processingregion 320 in which plasma may be generated. The substrate supportassembly may include an electrostatic chuck body 325, which may includeone or more components embedded or disposed within the body. Thecomponents incorporated within the top puck may not be exposed toprocessing materials in some embodiments, and may be fully retainedwithin the chuck body 325. Electrostatic chuck body 325 may define asubstrate support surface 327, and may be characterized by a thicknessand length or diameter depending on the specific geometry of the chuckbody. In some embodiments the chuck body may be elliptical, and may becharacterized by one or more radial dimensions from a central axisthrough the chuck body. It is to be understood that the top puck may beany geometry, and when radial dimensions are discussed, they may defineany length from a central position of the chuck body.

Electrostatic chuck body 325 may be coupled with a stem 330, which maysupport the chuck body and may include channels as will be discussedbelow for delivering and receiving electrical and/or fluid lines thatmay couple with internal components of the chuck body 325. Chuck body325 may include associated channels or components to operate as anelectrostatic chuck, although in some embodiments the assembly mayoperate as or include components for a vacuum chuck, or any other typeof chucking system. Stem 330 may be coupled with the chuck body on asecond surface of the chuck body opposite the substrate support surface.The electrostatic chuck body 325 may include an electrode 335, which maybe a DC electrode, embedded within the chuck body proximate thesubstrate support surface. Electrode 335 may be electrically coupledwith a power source 340. Power source 340 may be configured to provideenergy or voltage to the electrically conductive chuck electrode 335.This may be operated to form a plasma of a precursor within theprocessing region 320 of the semiconductor processing chamber 300,although other plasma operations may similarly be sustained. Forexample, electrode 335 may also be a chucking mesh that operates aselectrical ground for a capacitive plasma system including an RF source307 electrically coupled with showerhead 305. For example, electrode 335may operate as a ground path for RF power from the RF source 307, whilealso operating as an electric bias to the substrate to provideelectrostatic clamping of the substrate to the substrate supportsurface. Power source 340 may include a filter, a power supply, and anumber of other electrical components configured to provide a chuckingvoltage.

In operation, a substrate may be in at least partial contact with thesubstrate support surface of the electrostatic chuck body, which mayproduce a contact gap, which may essentially produce a capacitive effectbetween a surface of the pedestal and the substrate. Voltage may beapplied to the contact gap, which may generate an electrostatic forcefor chucking. The power supply 340 may provide electric charge thatmigrates from the electrode to the substrate support surface where itmay accumulate, and which may produce a charge layer having Coulombattraction with opposite charges at the substrate, and which mayelectrostatically hold the substrate against the substrate supportsurface of the chuck body. This charge migration may occur by currentflowing through a dielectric material of the chuck body based on afinite resistance within the dielectric for Johnsen-Rahbek typechucking, which may be used in some embodiments of the presenttechnology.

Chuck body 325 may also define a recessed region 345 within thesubstrate support surface, which may provide a recessed pocket in whicha substrate may be disposed. Recessed region 345 may be formed at aninterior region of the top puck and may be configured to receive asubstrate for processing. Recessed region 345 may encompass a centralregion of the electrostatic chuck body as illustrated, and may be sizedto accommodate any variety of substrate sizes. A substrate may be seatedwithin the recessed region, and contained by an exterior region 347,which may encompass the substrate. In some embodiments the height ofexterior region 347 may be such that a substrate is level with orrecessed below a surface height of the substrate support surface atexterior region 347. A recessed surface may control edge effects duringprocessing, which may improve uniformity of deposition across thesubstrate in some embodiments. In some embodiments, an edge ring may bedisposed about a periphery of the top puck, and may at least partiallydefine the recess within which a substrate may be seated. In someembodiments, the surface of the chuck body may be substantially planar,and the edge ring may fully define the recess within which the substratemay be seated.

In some embodiments the electrostatic chuck body 325 and/or the stem 330may be insulative or dielectric materials. For example, oxides,nitrides, carbides, and other materials may be used to form thecomponents. Exemplary materials may include ceramics, including aluminumoxide, aluminum nitride, silicon carbide, tungsten carbide, and anyother metal or transition metal oxide, nitride, carbide, boride, ortitanate, as well as combinations of these materials and otherinsulative or dielectric materials. Different grades of ceramicmaterials may be used to provide composites configured to operate atparticular temperature ranges, and thus different ceramic grades ofsimilar materials may be used for the top puck and stem in someembodiments. Dopants may be incorporated in some embodiments to adjustelectrical properties as will be explained further below. Exemplarydopant materials may include yttrium, magnesium, silicon, iron, calcium,chromium, sodium, nickel, copper, zinc, or any number of other elementsknown to be incorporated within a ceramic or dielectric material.

Electrostatic chuck body 325 may also include an embedded heater 350contained within the chuck body. Heater 350 may include a resistiveheater or a fluid heater in embodiments. In some embodiments theelectrode 335 may be operated as the heater, but by decoupling theseoperations, more individual control may be afforded, and extended heatercoverage may be provided while limiting the region for plasma formation.Heater 350 may include a polymer heater bonded or coupled with the chuckbody material, although a conductive element may be embedded within theelectrostatic chuck body and configured to receive current, such as ACcurrent, to heat the top puck. The current may be delivered through thestem 330 through a similar channel as the DC power discussed above.Heater 350 may be coupled with a power supply 365, which may providecurrent to a resistive heating element to facilitate heating of theassociated chuck body and/or substrate. Heater 350 may include multipleheaters in embodiments, and each heater may be associated with a zone ofthe chuck body, and thus exemplary chuck bodies may include a similarnumber or greater number of zones than heaters. The chucking meshelectrode 335 may be positioned between the heater 350 and the substratesupport surface 327 in some embodiments, and a distance may bemaintained between the electrode within the chuck body and the substratesupport surface in some embodiments as will be described further below.

The heater 350 may be capable of adjusting temperatures across theelectrostatic chuck body 325, as well as a substrate residing on thesubstrate support surface 327. The heater may have a range of operatingtemperatures to heat the chuck body and/or a substrate above or about100° C., and the heater may be configured to heat above or about 125°C., above or about 150° C., above or about 175° C., above or about 200°C., above or about 250° C., above or about 300° C., above or about 350°C., above or about 400° C., above or about 450° C., above or about 500°C., above or about 550° C., above or about 600° C., above or about 650°C., above or about 700° C., above or about 750° C., above or about 800°C., above or about 850° C., above or about 900° C., above or about 950°C., above or about 1000° C., or higher. The heater may also beconfigured to operate in any range encompassed between any two of thesestated numbers, or smaller ranges encompassed within any of theseranges. In some embodiments, as will be described further below, thechuck heater may be operated to maintain a substrate temperature aboveat least 500° C. during deposition operations, such as forming stacks ofmaterial for memory devices as previously described.

FIG. 4 shows a schematic partial cross-sectional view of an exemplarysubstrate support assembly 400 according to some embodiments of thepresent technology. Substrate support assembly 400 may include any ofthe materials or components previously described, and may illustrateadditional details of substrate support assemblies previously discussed.As illustrated, an electrostatic chuck body 405 may include an embeddedelectrode 410 and an embedded heater 415 as previously described. Asubstrate support surface 406 may be defined by the chuck body and maybe configured to support a semiconductor substrate 430. The substratesupport surface may define a recessed pocket 408 within the substratesupport surface. A recessed ledge 420 may be defined in the substratesupport surface as well. The recessed ledge may extend radially inwardfrom an outer radial edge of the recessed pocket. Additionally, thesubstrate support surface may define a number of protrusions 425extending from the substrate support surface within the recessed pocket408. An exposed surface across the protrusions 425 may define contactlocations where substrate 430 may contact the substrate support surface.

As described above, a power supply may be provided for each of theheater 415 and the electrode 410 in embodiments, which may be any numberof power supplies. For example, the power supply for the electrode maybe a DC power supply, or any other power supply, and may provide avoltage range configured to chuck a substrate to the substrate supportsurface 406. For example, a relatively higher power supply may be usedfor systems according to some embodiments of the present technology tofacilitate chucking substrates having thicker deposition layers, whichmay be characterized by greater stress contributing to bowing. As onenon-limiting example, for ON stacks, as the number of pairs of layersincreases, the forces acting on the substrate may increase. Highertemperatures may contribute to these forces, further increasing theamount of bowing, and challenging the capability to properly chuck thesubstrate to the support assembly.

To compensate for these forces, an increased chucking voltage may beused to maintain a substantially planar substrate surface, although anamount of bowing may still occur. As these layer pairs continue toincrease, the minimum voltage to maintain chucking may continue toincrease. Consequently, in some embodiments a minimum chucking voltagemay be above or about −250 V, and depending on the stress and number ofpairs to compensate, the minimum chucking voltage may be greater than orabout −300 V, greater than or about −350 V, greater than or about −400V, greater than or about −450 V, greater than or about −500 V, greaterthan or about −550 V, greater than or about −600 V, greater than orabout −650 V, greater than or about −700 V, greater than or about −750V, greater than or about −800 V, greater than or about −850 V, greaterthan or about −900 V, greater than or about −950 V, greater than orabout −1,000 V, or more.

As noted above, however, these deposition operations may be performed atincreased temperatures, which may directly impact the resistivity of thechuck body material, and the ability of this material to operateappropriately as a J-R chuck. For example, electrostatic chuck body 405may be aluminum nitride, for example, which may be characterized by abulk resistance at a certain temperature. As the temperature of thematerial increases, resistance drops, and may drop significantly attemperatures above 500° C., for example. As the resistance drops, alikelihood of electrostatic discharge or arcing may increase.Additionally, to limit the substantial bowing of a substrate that mayotherwise occur during these depositions, increased voltage may be usedto maintain chucking. However, as this voltage is increased, thelikelihood of arcing may similarly increase about the region of ledge420, which may limit the amount of voltage that may be applied forchucking, and which may limit the ability to counteract bowing. This hasconventionally led to damage and reduced quality of production.

However, the present technology utilizes materials and configurationsthat may facilitate an increased voltage window without leading toarcing compared to conventional technology. For example, conventionaltechnology may exhibit arcing at clamping voltages above or about −300V, or about −350 V. This voltage may be insufficient to compensate forthe film stresses generated during deposition of multi-layer stacks,such as for ON deposition with tens or hundreds of layers of material.The present technology may facilitate chucking at voltages of betweenabout −500 V to about −1000 V, and including between about −600 V toabout −800 V, which may accommodate stresses associated with greaternumbers of deposition layers, while limiting arcing from the pedestal.

For J-R chucking, chucking force generally increases to a saturationlevel as temperature increases due to the resistance changes within thepedestal material facilitating charge migration to the surface of thechuck body, such as protrusions 425 that may directly contact thesubstrate. However, this has conventionally led to arcing about thesubstrate when chucking voltage is increased to levels to accommodateincreased substrate bowing. The present technology improves on thesedeficiencies providing assemblies that may operate at increased chuckingvoltages to compensate for increased substrate stresses by reducingleakage current in the substrate support assembly. Leakage current is anindicator of migration within a substrate support material, which may bemeasured from leakage occurring from the electrode to the heater.

Conventional technologies may accept leakage currents of greater than orabout 10 mA at particular operating temperatures, which may increasedramatically at operating temperatures above 500° C. While conventionaltechnologies may consider leakage current from a perspective ofinsulation layer damage or substrate damage, relatively high leakagecurrents may be accepted in an attempt to boost chucking force. However,this has led to increased arcing in conventional designs. The presenttechnology modifies aspects and characteristics of the substrate supportassembly to limit leakage current by effectively increasing resistivityof the substrate support materials to limit leakage current whilemaintaining chucking force at the substrate. Accordingly, the presenttechnology produces substrate support assemblies characterized by aresistivity based on leakage current that is maintained within a rangeto adequately chuck a substrate characterized by stresses as previouslydescribed, while also limiting or preventing arcing due to higherchucking voltages.

The present technology may limit leakage current at temperatures greaterthan or about 500° C., and may limit leakage current at temperaturesgreater than or about 550° C., greater than or about 600° C., greaterthan or about 650° C., greater than or about 700° C., greater than orabout 750° C., or higher. The present technology may also limit leakagecurrent at chucking voltages of greater than or about 400 V, and maylimit leakage current at chucking voltages of greater than or about 450V, greater than or about 500 V, greater than or about 550 V, greaterthan or about 600 V, greater than or about 650 V, greater than or about700 V, greater than or about 750 V, greater than or about 800 V, greaterthan or about 850 V, greater than or about 900 V, or higher. The presenttechnology may limit leakage current within these temperature andvoltage ranges to less than or about 10 mA, and may limit leakagecurrent to less than or about 8 mA, less than or about 6 mA, less thanor about 5 mA, less than or about 4 mA, less than or about 3.5 mA, lessthan or about 3 mA, less than or about 2.5 mA, less than or about 2 mA,less than or about 1.5 mA, or less. However, in some embodiments theleakage current may be maintained greater than or about 0.2 mA to ensureadequate migration to facilitate J-R chucking, and in some embodimentsmay maintain leakage currents greater than or about 0.3 mA, greater thanor about 0.5 mA, greater than or about 0.7 mA, greater than or about 1.0mA, or higher.

As noted above, J-R chucking may be at least partially based on aresistance of a contact layer provided between the substrate and thepedestal. By adjusting the distance of the electrode from the contactsurface of the electrostatic chuck body, the resistance may be adjusted.Based on the increased temperatures of some embodiments of the presenttechnology, the chucking force may be substantially maintained orminimally lowered as the regime may be along a relative plateau ofchucking force. Consequently, in some embodiments, the electrode may beembedded further from a contact surface in some embodiments, which mayeffectively increase resistance of the substrate support assembly toreduce leakage currents that may contribute to arcing.

For example, as illustrated in FIG. 4, a contact surface may be formedalong an outermost, such as an uppermost, surface of the substratesupport assembly in the recessed pocket 408, which may be a top surfaceof the protrusions 425. From this plane, the electrode 410 may beembedded a certain depth within the substrate support assembly tomaintain a minimum distance between the electrode and the substratesupport surface. For example, in some embodiments the electrode 410 maybe embedded within the electrostatic chuck body a distance or depth fromthe substrate support surface 406 of greater than or about 2 mm, and maybe embedded a distance greater than or about 3 mm, greater than or about4 mm, greater than or about 5 mm, greater than or about 6 mm, greaterthan or about 7 mm, greater than or about 8 mm, greater than or about 9mm, greater than or about 10 mm, greater than or about 12 mm, greaterthan or about 14 mm, greater than or about 16 mm, greater than or about18 mm, greater than or about 20 mm, or more from the substrate supportsurface, depending on characteristics of the substrate support assembly.

Electrostatic chuck body 405 may also be or include materialscharacterized by a particular volumetric resistivity. As noted above,the chuck body may be or include a ceramic material, such as aluminumnitride, or any of the materials discussed above. In some embodiments,the materials may be selected, doped, or produced, such as sintered, toprovide a volumetric resistivity above a threshold. For example, in someembodiments, the chuck body may be or include a dielectric material,such as an aluminum nitride material, characterized by a volumetricresistivity greater than or about 5×10⁸ ohm-cm at a temperature ofgreater than or about 550° C., greater than or about 600° C., greaterthan or about 650° C., or more, and which may be characterized by avolumetric resistivity greater than or about 1×10⁹ ohm-cm, greater thanor about 5×10⁹ ohm-cm, greater than or about 1×10¹⁰ ohm-cm, greater thanor about 3×10¹⁰ ohm-cm, greater than or about 5×10¹⁰ ohm-cm, greaterthan or about 7×10¹⁰ ohm-cm, greater than or about 1×10¹¹ ohm-cm,greater than or about 3×10¹¹ ohm-cm, greater than or about 5×10¹¹ohm-cm, greater than or about 7×10¹¹ ohm-cm, greater than or about1×10¹² ohm-cm, or greater at any of these temperature ranges.

An effective resistivity may also be accommodated by adjusting theamount of contact between a substrate and the substrate supportassembly, for example. As illustrated in FIG. 4, a number of protrusions425 may be included or defined along the substrate support surface 406.The protrusions may provide points of contact across a planar area of asubstrate support surface or the recessed pocket. Consequently, thesubstrate may be in contact with the substrate support assembly along apercentage of the surface area of the substrate. Conventionaltechnologies may provide a variety of high contact, such as above orabout 60% contact, medium contact, such as around 40% contact, and lowcontact, which may be less than 20% contact. However, each of theseranges may provide increased leakage current compared to the presenttechnology. Alternative low contact systems providing less than 1%contact may also be insufficient as these systems may not producesufficient clamping forces to accommodate the bowing of substrates. Thepresent technology may increase a surface area contact percentage forJ-R chucking, while additionally adjusting characteristics of theclamping with the protrusion pattern.

A substrate 430 positioned on substrate support surface 406 may contacteach of the protrusions 425, and may additionally extend at leastpartially across ledge 420 within recessed pocket 408. The presenttechnology may increase the contact percentage along the wafer byincreasing a number of protrusions. For example, the present technologymay form protrusions characterized by a diameter or width of about 1 mm,about 2 mm, or more, and may in some embodiments include a combinationof protrusions characterized by a diameter of greater than or about 1 mmand protrusions characterized by a diameter of greater than or about 2mm. The protrusions may be characterized by any number of geometries andprofiles in embodiments of the present technology. For an exemplarysubstrate support assembly, the substrate support surface within therecessed pocket may define greater than or about 250 protrusions, andmay define greater than or about 500 protrusions, greater than or about750 protrusions, greater than or about 1,000 protrusions, greater thanor about 1,250 protrusions, greater than or about 1,500 protrusions,greater than or about 1,750 protrusions, greater than or about 2,000protrusions, or more. The protrusions may be defined in any number offormations or patterns including uniform patterns as well as generaldistributions across the surface.

Additionally, an outermost subset 427 of protrusions 425 may bemaintained a distance less than or about 5 mm from an inner radial edgeof ledge 420, adjacent the protrusions. In some embodiments, anoutermost subset of protrusions may be maintained a distance less thanor about 4.5 mm from the inner radial edge of ledge 420, and may bemaintained less than or about 4.0 mm, less than or about 3.5 mm, lessthan or about 3.0 mm, less than or about 2.5 mm, less than or about 2.0mm, less than or about 1.5 mm, less than or about 1.0 mm, or less fromthe inner radial edge of ledge 420. By maintaining the protrusionswithin this distance, torque on an outermost area of a substrate may bemaintained or increased, which may further facilitate clamping tocompensate substrate bowing.

By producing protrusions according to some embodiments of the presenttechnology, a percentage of contact along a surface of a substrate maybe increased to greater than or about 1.0%, and may be greater than orabout 1.5%, greater than or about 2.0%, greater than or about 2.5%,greater than or about 3.0%, greater than or about 3.5%, greater than orabout 4.0%, greater than or about 4.5%, greater than or about 5.0%, orgreater. The percentage of contact may be maintained below or about 10%to limit leakage current below the previously stated ranges, and maylimit contact below or about 8%, below or about 6%, below or about 5%,or less. When not including an amount of contact along ledge 420, thepercentage contact provided by the protrusions may be maintained greaterthan or about 0.2% of the surface area of the substrate surface alongthe substrate support assembly. In some embodiments the percentagecontact provided by the protrusions excluding the ledge contribution maybe maintained at greater than or about 0.3%, greater than or about 0.4%,greater than or about 0.6%, greater than or about 0.8%, greater than orabout 1.0%, greater than or about 1.2%, greater than or about 1.4%,greater than or about 1.6%, greater than or about 1.8%, greater than orabout 2.0%, greater than or about 2.2%, greater than or about 2.4%,greater than or about 2.6%, greater than or about 2.8%, greater than orabout 3.0%, or greater. By providing substrate support assembliescharacterized by controlled leakage currents, the present technology mayprovide an increased chucking window that may suitably chuck substratescharacterized by increased film stresses, while limiting or preventingarcing within a plasma environment.

FIG. 5 shows a schematic partial cross-sectional view of an exemplarysubstrate support assembly 500 according to some embodiments of thepresent technology. Substrate support assembly 500 may include any ofthe materials or components previously described, and may illustrateadditional details of substrate support assemblies previously discussed.For example, the previously discussed protrusions may be distributedacross the surface of the substrate support in any pattern. Although auniform distribution may be used, in some embodiments a non-uniform ofprotrusions may be used. FIG. 5 illustrates one exemplary distributionencompassed by the present technology, where the protrusions 525 may bedistributed in a pattern of rings extending radially outward on thesubstrate support. Each ring may have more or less protrusions than aradially inward ring, and the distribution may increase in density at anouter region of the substrate support. For example, as illustrated, aradially outer portion of the substrate support may include an increaseddensity of protrusions, which may improve chucking as previouslydescribed. Any number of other distribution patterns are similarlyencompassed by the present technology.

In the preceding description, for the purposes of explanation, numerousdetails have been set forth in order to provide an understanding ofvarious embodiments of the present technology. It will be apparent toone skilled in the art, however, that certain embodiments may bepracticed without some of these details, or with additional details.

Having disclosed several embodiments, it will be recognized by those ofskill in the art that various modifications, alternative constructions,and equivalents may be used without departing from the spirit of theembodiments. Additionally, a number of well-known processes and elementshave not been described in order to avoid unnecessarily obscuring thepresent technology. Accordingly, the above description should not betaken as limiting the scope of the technology.

Where a range of values is provided, it is understood that eachintervening value, to the smallest fraction of the unit of the lowerlimit, unless the context clearly dictates otherwise, between the upperand lower limits of that range is also specifically disclosed. Anynarrower range between any stated values or unstated intervening valuesin a stated range and any other stated or intervening value in thatstated range is encompassed. The upper and lower limits of those smallerranges may independently be included or excluded in the range, and eachrange where either, neither, or both limits are included in the smallerranges is also encompassed within the technology, subject to anyspecifically excluded limit in the stated range. Where the stated rangeincludes one or both of the limits, ranges excluding either or both ofthose included limits are also included.

As used herein and in the appended claims, the singular forms “a”, “an”,and “the” include plural references unless the context clearly dictatesotherwise. Thus, for example, reference to “a heater” includes aplurality of such heaters, and reference to “the protrusion” includesreference to one or more protrusions and equivalents thereof known tothose skilled in the art, and so forth.

Also, the words “comprise(s)”, “comprising”, “contain(s)”, “containing”,“include(s)”, and “including”, when used in this specification and inthe following claims, are intended to specify the presence of statedfeatures, integers, components, or operations, but they do not precludethe presence or addition of one or more other features, integers,components, operations, acts, or groups.

The invention claimed is:
 1. A substrate support assembly comprising: anelectrostatic chuck body defining a substrate support surface; a supportstem coupled with the electrostatic chuck body; a heater embedded withinthe electrostatic chuck body; and an electrode embedded within theelectrostatic chuck body between the heater and the substrate supportsurface, wherein the substrate support assembly is characterized by aleakage current through the electrostatic chuck body of less than orabout 4 mA at a temperature of greater than or about 500° C. and avoltage of greater than or about 600 V.
 2. The substrate supportassembly of claim 1, wherein the electrostatic chuck body defines arecessed pocket along the substrate support surface encompassing acentral region of the electrostatic chuck body.
 3. The substrate supportassembly of claim 2, wherein the substrate support surface defines arecessed ledge extending radially inward from an outer radial edge ofthe recessed pocket.
 4. The substrate support assembly of claim 3,wherein the electrostatic chuck body defines a plurality of protrusionsextending from the substrate support surface within the recessed pocket.5. The substrate support assembly of claim 4, wherein a distance betweena radially outermost protrusion and in inner radial edge of the recessedledge is maintained below or about 3 mm.
 6. The substrate supportassembly of claim 4, wherein the electrostatic chuck body definesgreater than or about 500 protrusions, and wherein each protrusion ofthe plurality of protrusions is characterized by a diameter of greaterthan or about 1 mm.
 7. The substrate support assembly of claim 6,wherein a subset of protrusions of the plurality of protrusions arecharacterized by a diameter of greater than or about 2 mm.
 8. Thesubstrate support assembly of claim 4, wherein the plurality ofprotrusions define a contact area for a substrate seated on thesubstrate support surface of the electrostatic chuck body, and whereinthe contact area is less than or about 10% of a planar area of thesubstrate.
 9. The substrate support assembly of claim 1, wherein theelectrostatic chuck body comprises a ceramic material.
 10. The substratesupport assembly of claim 9, wherein the ceramic material comprisesaluminum nitride.
 11. The substrate support assembly of claim 9, whereinthe ceramic material is characterized by a volumetric resistivity ofgreater than or about 1×10⁹ ohm-cm at a temperature of greater than orabout 550° C.
 12. A substrate support assembly comprising: anelectrostatic chuck body defining a substrate support surface; a heaterembedded within the electrostatic chuck body; and an electrode embeddedwithin the electrostatic chuck body between the heater and the substratesupport surface, wherein the electrode is maintained a distance of atleast about 3 mm from the substrate support surface within theelectrostatic chuck body, and wherein the substrate support assembly ischaracterized by a leakage current through the electrostatic chuck bodyof less than or about 4 mA at a temperature of greater than or about540° C. and a voltage of greater than or about 660 V.
 13. The substratesupport assembly of claim 12, wherein the electrode is positioned withinthe electrostatic chuck body at a depth of at least about 5 mm from thesubstrate support surface of the electrostatic chuck body.
 14. Thesubstrate support assembly of claim 12, wherein the electrostatic chuckbody comprises a ceramic material characterized by a volumetricresistivity of greater than or about 1×10⁹ ohm-cm at a temperature ofgreater than or about 600° C.
 15. The substrate support assembly ofclaim 12, wherein the electrostatic chuck body defines a recessed pocketwithin the substrate support surface configured to receive a substratefor processing.
 16. The substrate support assembly of claim 15, whereinthe substrate support surface defines a recessed ledge extendingradially inward from an outer radial edge of the recessed pocket. 17.The substrate support assembly of claim 16, wherein the electrostaticchuck body defines a plurality of protrusions extending from thesubstrate support surface within the recessed pocket.
 18. The substratesupport assembly of claim 17, wherein the plurality of protrusionsdefine a contact area for a substrate seated on the substrate supportsurface of the electrostatic chuck body, and wherein the contact area isless than or about 5% of a planar area of the substrate.
 19. Thesubstrate support assembly of claim 12, wherein the substrate supportassembly is characterized by a leakage current through the electrostaticchuck body of less than or about 4 mA at a temperature of greater thanor about 600° C. and a voltage of greater than or about 800 V.
 20. Asubstrate support assembly comprising: an electrostatic chuck bodydefining a substrate support surface; a support stem coupled with theelectrostatic chuck body; a heater embedded within the electrostaticchuck body; and an electrode embedded within the electrostatic chuckbody between the heater and the substrate support surface, wherein theelectrode is maintained a distance of at least about 5 mm from thesubstrate support surface within the electrostatic chuck body, andwherein the substrate support assembly is characterized by a leakagecurrent through the electrostatic chuck body of less than or about 4 mAat a temperature of greater than or about 550° C. and a voltage ofgreater than or about 650 V.